Piston



Feb 15, W44- H. D. BRANDT ETAL PISTQN Filed June 26, 1942 FICA.

FIG.4.

FIGB.

INVENTOR. H. D. BRANDT J. L..WEI NMANN enema Feb. 15,19441 This invention relates to pistOns and for its principal object to produce apiston which offers greater resistance to wear than the pistons s cam-, (on. ace- 14); 7 g

- andit will be readily understood that said-apertures 3. and sleeves 3f'are disposed, respectively,

1 opposite each other since they are associated now in use. Wear is the outstanding handicap in all pistons, and while it cannot be eliminated entirely, by the use of the present invention; it can be retarded by providing piston skirts of greater hardness, flexibility, and resiliency than is pos-' In our invention the skirt, instead of being rigid and integrally formed with the head of the piston, is

sible in the pistons now in general use.

made of a different material than the head and attached to the head.

It is well known that the greater amountof wall contact with the enclosing cylinder a piston can ofier, the more effective a seal will be mainl tained and the less of the gasifled explosive charge will escape. By the use of our invention with the oppositely'positioned lugs 3. Each of' the lugs 2 and} is provided with a groove 4 adapted to assist in the operation'of assembling the head and skirt portion of the piston. Each groove .4 extends from the side edge of 9. lug 2 or 3, re-

spectively, to a point approximately halfway across'said lug, where it terminates in a bore 5.

' All the parts mentioned-thus far are integrally formed, preferably of' cast iron; and are clearly the resilient skirt of the piston offers a more.

continuous wall contact at all points. allowing,

of course, for the thin film of oil that must be present between thepiston and cylinder in all combustionengines, and thus almost perfect sealing is effected. A further advantage is the ease with which a worn skirt can be removed from illustrated in Figs. '1 and 2. I

The'skirt'S of our piston is preferably formed 'ofsteel or some other suit-able material which has a' greater degree of flexibility and resiliency than cast iron. The skirt S is provided with slits 6 which permit expansion thereof, and each slit terminates at its upper endin an aperture 1 of slightly greater diameter than the slit, the purpose of the apertures I being to diffuse the strain incident to expansion and thus prevent splitting a piston and replaced by a new one, entailing the 7 minimum of loss of time. 7

Fig. 11s a side elevation of the head of our piston as it appears before the skirt is attached thereto. p

Fig. 2 is a view similar to Fig. 1, but illustrat ing the head as it appears when it has been rotated one-fourth of a revolution. r

Fig. 3 is aside elevation of the skirt portionv of the piston illustrating particularly theexpansion means.

Fig. 4 is a sectional view taken on linexl-Q, Fig. 5, illustrating the head and skirt portionof the piston in attached relation. W

Fig. is a cross-sectional view taken on line 5-5, Fig. 4; j

In the drawing A designates the headof the piston, which is provided with the usual grooves I for the reception of piston rings. At the outer circumference of the head A oppositely disposed lugs I depend from said head, and intermediate of the lugs 2 and also at the outer circumference and a sleeve 3' extending inwardly from. said 7 aperture 3' 'a short distance, said apertures and sleeves being of such size as to receive the usual of the skirt S. "The skirt S has a plurality of countersinks in its circular wall so formed as to provide slight protuberances 8 on the inner side of said. wa1l,'which protuberances are adapted to register with the grooves 4 above mentioned, and

at the center of each countersink a bore is formed which is adapted to registerwith one of the apertures 15 mentioned above when the head A and skirt S are assembled. The skirt S also has oppositely disposed, circularj apertures 9 which will register with the apertures 3'. in the lugs 3 when the head A and skirt 3 are assembled.

when the head And skirt S are to be assembled, the procedure is as follows:

The skirt S is slipped up over the lower portion of the head A until the protuberances 8 register slidably with the grooves 4, when the skirt is rotated a sufllcient distance to bring the bores in the countersinks of the skirt into registration with'the bores 5 in the lugs 2 and 3, respectively.

Locking bolts or screws III are then passed through the several registering bores and apertures to hold the head A and skirt S securely to; gether. This willbring the apertures 9, the apertures I, and the sleeves! into registration, so that the pin associated with the crank arm of the engine (not shown) can bepassed therethrough (Fig. 4). An expansion ring R may then be inserted into the skirt S near its lower portion in the usual manner, but as this does not form a part of the present invention it will not be described. The piston is now ready to be inserted pin which is associated with the usual crank bar, into an engine cylinder, and by virtue of the slits -terial forming the skirt 8, suilicient expansion of said skirt is permitted to force it into close contact with the cylinder wall, thus effecting a more nearly perfect seal than could be obtained it the skirt S were formed of the same rigid material as the head A. The piston rings ordinarily used are, of course, inserted in the grooves I of the head to assist in maintaining the seal.

We claim:

1. A piston comprising a head and a flexible. resilient skirt portion detachably secured to said head, a plurality of members depending from said head and formed integral therewith, said depending members having means for attaching said head to said skirt portion, two of said depending members being oi greater length than the other of said depending members and having elements adapted for the reception of a crank pin, said skirt portion having attaching means associated with the attaching means on said head and being provided with apertures registering with the pinreceiving elements on the depending members of said head, and said-skirt portion having slits terminating in circular apertures to permit expan sion of said skirt portion. I

2. Apiston comprising a head and a flexible, resilient skirt portion detachably secured to said head, a plurality of members depending from said head and formed integral therewith, said depending members having bolt-receiving apertures tor attaching said head to said skirt portiomtwo or said depending members being of greater length than the other of said depending mem-' bers and having apertures near their lower extremities, sleeves extending inwardly from said last mentioned apertures adapted to receive a crank pin, said skirt portion having bolt-receiving apertures registering with thebolt-receiving apertures in said depending members of said head, said skirt portion being provided with apertures registering with said sleeves and their associated apertures in said depending members, and said skirt portion having slits terminating in circular ing means associated with the attaching means.

on said head. and said skirt portion being provided withapertures registering with the pin-receiving elements on the depending members or said head.

HERMAN D. BRANDT. JOHN L. WEINMANN. 

